Article
Thermodynamics
Prashant Saini, Atul Dhar, Satvasheel Powar
Summary: This study proposes novel configurations of a curved trapezoidal winglet vortex generator to improve heat transfer in fin and tube heat exchangers. By comparing different design configurations, it is found that the curved trapezoidal winglet vortex generator with multiple circular holes performs well in terms of thermohydraulic performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Jiafeng Wu, Peng Liu, Minjie Yu, Zhichun Liu, Wei Liu
Summary: This paper proposes an original sinusoidal wavy winglet type vortex generator to achieve high heat transfer performance with moderate increased pressure drop penalty for fin-and-tube heat exchangers. The study explores the effects of different parameters and the enhancement of convective heat transfer using vortex generators. The results show improved energy efficiency and heat transfer performance compared to conventional fins.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Energy & Fuels
Rishikesh Sharma, Dipti Prasad Mishra, Marek Wasilewski, Lakhbir Singh Brar
Summary: The present work aims to optimize the geometry of curved trapezoidal winglets to improve heat transfer efficiency (expressed as Colburn factor, j) and reduce pressure losses (expressed as friction factor, f). A fin-and-tube heat exchanger with winglets mounted on alternate tubes and fins is analyzed, and multi-objective optimization is performed using the genetic algorithm (GA) to maximize j and minimize f. Two surrogate models, response surface methodology (RSM) and artificial neural network (ANN), are used as inputs to GA. A sensitivity analysis is conducted to select the most influential geometrical parameters for optimization and reduce the number of experimental runs. The values of j and f in the design of the experiments table are calculated using CFD. The Pareto front points show a significant improvement compared to the reference model, providing a wide choice for designers in both design and off-design inlet conditions.
Article
Energy & Fuels
Josip Batista, Anica Trp, Kristian Lenic
Summary: The aim of this study is to analyze fluid flow and heat transfer characteristics in a fin-and-tube heat exchanger with delta-winglet type vortex generators. The results show that the DWD configuration with an attack angle of 45 degrees achieves the best heat transfer performance.
Article
Chemistry, Multidisciplinary
Yun-Seok Choi, Youn-Jea Kim
Summary: The study analyzed the heat transfer performance of a fin-tube heat exchanger using ferrofluid as a coolant under external magnetic fields, observing changes in the thermal boundary layer and formation of vortices that activate thermal diffusion, enhancing heat transfer efficiency.
APPLIED SCIENCES-BASEL
(2021)
Article
Thermodynamics
Ahmet Umit Tepe, Harun Yilmaz
Summary: This study numerically investigated the heat transfer performance of circular-slice-shaped-winglet for tube bank heat exchanger. The optimal design was obtained by analyzing various geometric parameters. The results showed that the CSSW winglet design significantly improved the performance of the heat exchanger.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Yeongtaek Oh, Kuisoon Kim
Summary: In this study, the thermal and fluid-flow characteristics of different curved vortex generators (CVGs) were computationally analyzed, and it was found that the position of CVGs has a significant impact on the heat transfer performance. DWU CVGs and DWD CVGs show improvements in heat transfer performance compared to conventional VGs, but certain position and geometry requirements must be met for optimal performance to be achieved.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Ashish J. Modi, Manish K. Rathod
Summary: This study investigates the influence of a modified rectangular winglet vortex generator on the heat transfer and pressure drop performance of a fin-tube heat exchanger. The experimental results demonstrate that the use of the vortex generator significantly enhances the heat transfer coefficient of the heat exchanger while causing an increase in pressure loss.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Pongjet Promvonge, Pitak Promthaisong, Sompol Skullong
Summary: The article investigates the effect of insertion of louvered V-winglet (LVW) vortex generators on convection heat transfer and pressure loss in a tubular heat exchanger. The experimental result shows that among the LVWs, the case of R-P=0.5, theta=10 degrees provides the largest friction factor and Nusselt number.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Ahmet Umit Tepe
Summary: This study investigated the effect of a newly proposed punched triangular ramp vortex generator on heat transfer performance for a fin-tube heat exchanger through numerical simulations. The results showed that the ramp angle had a more significant influence on thermo-hydraulic performance compared to ramp height.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Pongjet Promvonge, Sompol Skullong
Summary: This study investigates the thermohydraulic performance, flow friction, and entropy generation analysis of a heated tube with louvered winglet tape inserts. The results show that different louver angles and pitch ratios have a significant impact on heat transfer rates and friction losses. Decreasing Reynolds number, pitch ratio, and louver angle can reduce entropy generation.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Lumei Zhao, Zuoqin Qian, Xinyu Wang, Qiang Wang, Changyi Li, Zhicheng Zhang
Summary: A novel combination of curved and straight rectangular winglet vortex generator (RWVG) pairs was used to enhance the comprehensive performance of a fin-tube heat exchanger. Numerical investigations showed that RWVGs could improve heat transfer characteristics and comprehensive performance, and the location and size of RWVGs had a positive effect on the thermohydraulic characteristics.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Review
Green & Sustainable Science & Technology
Ali Sadeghianjahromi, Chi-Chuan Wang
Summary: Fin-and-tube heat exchangers are widely used for thermal energy conversion, with researches on different heat transfer enhancement mechanisms and discussions on the effects of geometric parameters.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Thermodynamics
Hemant Naik, Shaligram Tiwari
Summary: The study investigates the effects of winglet type vortex generators on fin-tube heat exchanger performance, emphasizing the importance of optimal winglet positions and inlet flow conditions in enhancing thermohydraulic performance. The relationship between heat transfer, secondary flow, and irreversibility parameters is analyzed to understand the overall impact on thermal performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Zhi-Min Lin, Sheng-Fan Li, Cai-Ping Liu, Liang-Bi Wang, Yong-Heng Zhang
Summary: The study reveals that CDVGs can enhance heat transfer performance by reducing recirculation area and generating strong longitudinal vortices, ultimately improving heat transfer ability in the recirculation zone of finned round tube heat exchangers. By using the optimal geometric parameters, the study shows that the thermal property factor can be increased by 1.35 compared to plain fin geometry when Reynolds number equals to 3000, under the same pumping power constraint.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Thermodynamics
Xiaoyu Jia, Mei Lin, Shiwei Su, Qiuwang Wang, Jian Yang
Summary: This paper numerically studies the electromagnetic-fluid-thermal-mechanical stress coupling process in an oil immersed transformer using finite element method. The analysis reveals that coil deformation is mainly caused by thermal load, with little impact from electromagnetic force. Stress at both ends of the coil is the highest, leading to potential fatigue failures.
Article
Thermodynamics
Di Qi, Jing He, Yongsheng Xu, Mei Lin, Qiuwang Wang
Summary: This study analyzed the design and performance of a ribbed channel heat sink, showing that increasing the rib diameter can improve heat transfer efficiency. The comprehensive heat transfer performance factor shows different trends under different heat flux densities and rib diameters, with the best heat transfer performance occurring at a rib diameter of 10mm.
Article
Mechanics
Xuefang Xu, Huaishuang Shao, Ruixiong Li, Mei Lin, Peiming Shi
Summary: Research on the crossflow of ventilation in high-speed trains revealed significant influences of suction, with crossflows without vanes showing more FM modulation and high-frequency AM modulation components. The increase in velocity and velocity ratio affect turbulent characteristics of crossflow, presenting high energy with a higher frequency of AM and FM.
JOURNAL OF TURBULENCE
(2022)
Article
Engineering, Mechanical
Xiao Liang, Jiaming Chu, Zhuo Zhou, Congfang Hu, Jinfeng Peng, Baixi Liu, Lin Mo, Jiu Hui Wu, Mei Lin
Summary: This paper investigates turbulent flow in a cavity Acoustic Black Hole (ABH) using numerical and experimental methods, exploring the low frequency sound energy dissipation mechanism under turbulence. The study shows that turbulence in ABH can isolate over 90% of low frequency sound waves, providing a technical solution for the isolation of low frequency sound waves.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Thermodynamics
Kexin Huang, Bo Su, Tong Li, Hanbing Ke, Mei Lin, Qiuwang Wang
Summary: Thermal stratification is the main cause of thermal fatigue failure in rectangular T-junctions. By setting an impeller with a constant rotation speed, the mixing behavior of hot and cold fluids can be improved, and various flow patterns including wall jet, deflecting jet, and impinging jet can be observed. The relationship between mixing length and blade diameter is not monotonic, and the optimal operating point is around D-p* = 0.5 for impellers with 2 blades.
APPLIED THERMAL ENGINEERING
(2022)
Article
Mechanics
Kexin Huang, Tong Li, Bo Su, Mei Lin, Qiuwang Wang
Summary: This study investigates coherent structures of turbulent mixing between cold and hot waters in a T-junction with a rotation impeller, with varying blade numbers (N-p = 2-4), using the dynamic mode decomposition method. The results show that increasing blade number leads to increased velocity fluctuation and initially increased and then decreased temperature fluctuation.
Article
Engineering, Chemical
Ming Liu, Mei Lin, Gary Owens, Zuliang Chen
Summary: Manganese tetroxide nanomaterials prepared by green tea extract were used to simultaneously degrade estriol and 17a-ethinylestradiol. The study found that divalent manganese played a key role in the catalytic process. The oxidation mechanism of E3/EE2 was also proposed.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Thermodynamics
Zhiwen Huang, Tong Li, Kexin Huang, Hanbing Ke, Mei Lin, Qiuwang Wang
Summary: This study proposes an accurate flow field and temperature field prediction method combining Dynamic Mode Decomposition (DMD) and deep learning. Through experimental comparison of flow field and temperature field prediction in a T-junction, it is found that the method combining DMD and ConvLSTM is the most accurate and stable prediction method.
Article
Environmental Sciences
Peng Wang, Fangyuan Yu, Yuan Chi, Xiao Wu, Mei Lin, Cong Lin, Tengfei Lin, Min Gao, Chunlin Zhao, Xiangqi Li
Summary: This study presents the synthesis of Bi0.5Na0.5TiO3@Ag composite through photoreduction of AgNO3 on Bi0.5Na0.5TiO3 nanoparticles, which showed enhanced efficiency for degrading obstinate pollutants in wastewater. The composite demonstrated a broadened absorption range, allowing for increased response to both UV and visible light. The piezo-potential induced by mechanical energy hindered carrier recombination, resulting in a high-efficiency synergistic piezo-photocatalytic process.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Thermodynamics
Zhenxing Zhao, Bin Hu, Jing He, Mei Lin, Hanbing Ke
Summary: In order to ensure the normal operation of electronic devices, it is crucial to design an efficient cooling system. This study analyzed the two-phase flow boiling performance of staggered pin finned channels using the Mixture multiphase model. The influence of different fin cross-section shapes (circular, triangular, diamond, and pentagonal) on flow boiling heat transfer, pressure drop, and temperature uniformity under different heat flux conditions were compared. The results showed that the pentagonal finned channel is the most effective in terms of heat transfer coefficient, pressure drop, and temperature uniformity.
APPLIED THERMAL ENGINEERING
(2023)
Article
Engineering, Environmental
Bo Su, Kexin Huang, Mei Lin, Qiuwang Wang
Summary: Flow mixing experiments were conducted to investigate the flow pattern evolution mechanisms in a T-junction with branch jet under steady and rolling motion conditions. The effects of fluid Reynolds number, inflow rate ratio, and rolling Reynolds number on flow pattern characteristics were discussed. New classification criteria of flow pattern under steady condition were proposed based on vortex structure evolution. The rolling motion caused the branch jet to periodically sweep up and down, enhancing flow instability in the T-junction, which could be inhibited by increasing fluid Reynolds number or decreasing inflow rate ratio and rolling Reynolds number. Additionally, the influence mechanisms of these parameters on flow pattern in the T-junction were investigated.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Nuclear Science & Technology
Bo Su, Mei Lin, Qiuwang Wang
Summary: The present study investigates the flow mixing characteristics in a T-junction under rolling motion condition with a momentum ratio of 0.95. The effects of inflow rates and the synergistic effects between velocity and temperature are discussed. The results show that rolling motion changes the velocity field, affects the mixing length of the temperature field, and increases the velocity fluctuation range while decreasing the temperature fluctuation range.
NUCLEAR ENGINEERING AND DESIGN
(2023)
Article
Thermodynamics
Ziliang Zhu, Shuang Wang, Kexin Huang, Dongjun Xu, Mei Lin, Qiuwang Wang
Summary: A novel regulation method using annular porous media and rotating impeller has been proposed for enhancing the thermal mixing performance of T-junctions. Results from large eddy turbulence model show that combining annular porous media and rotating impeller can have a synergistic effect in inhibiting temperature fluctuations near the wall and promoting thermal mixing in the mainstream zone.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
You Wang, Ziliang Zhu, Hanbing Ke, Mei Lin, Qiuwang Wang, Yining Wu
Summary: Compared with paraffin, water-based phase change energy storage (WPCES) is widely used in space-craft thermal control systems due to its higher latent heat. However, the volume expansion of water can lead to the formation of ice spikes, which can damage the enclosure of WPCES. This paper investigates the solidification process of water in cavities using a gas-liquid-solid numerical model and verifies the model through experiments. The formation mechanism of ice spikes is studied by considering gravitational acceleration and the aspect ratio of water space.
JOURNAL OF ENHANCED HEAT TRANSFER
(2023)
Article
Thermodynamics
Xiaoyu Jia, Jian Yang, Mei Lin, Qiuwang Wang
Summary: Metallic woven mesh screens, as representative porous media with periodic structures, have great potential in emerging technology and industrial equipment. This paper investigates the influence of stacking patterns and wire contact conditions on flow and heat conduction in these meshes, and proposes theoretical calculation models for macroscopic characteristics. The results show that flow characteristics are mainly affected by stacked patterns, and wire contact conditions significantly affect the z-direction thermal conductivity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hai Zhao, Puzhen Gao, Xiaochang Li, Ruifeng Tian, Hongyang Wei, Sichao Tan
Summary: This study numerically investigates the interaction between flow-induced vibration and forced convection heat transfer in a tube bundle. The results show that the impact of flow-induced vibration on heat transfer varies in different flow velocity regions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Rohit Chintala, Jon Winkler, Sugirdhalakshmi Ramaraj, Xin Jin
Summary: The current state of fault detection and diagnosis for residential air-conditioning systems is expensive and not suitable for widespread implementation. This paper proposes a cost-effective solution by introducing an automated fault detection algorithm as a screening step before more expensive tests can be conducted. The algorithm uses home thermostats and local weather information to identify thermodynamic parameters and detect high-impact air-conditioning faults.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
A. Azimi, N. Basiri, M. Eslami
Summary: This paper presents a novel optimization algorithm for improving the water-film cooling system of photovoltaic panels, resulting in a significant increase in net energy generation.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Duc-Thuan Phung, Chin-Hsiang Cheng
Summary: In this study, a novel CFDMD model is used to analyze and investigate the behavior of thermal-lag engines (TLE). The study shows that the CFDMD model effectively captures the thermodynamic behavior of the working gas and the dynamic behavior of the engine mechanism. Additionally, the study explores the temporal evolution of engine speed and the influence of various parameters on shaft power and brake thermal efficiency. The research also reveals the existence of a thermal-lag phenomenon in TLE.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Haiying Yang, Yinjie Shen, Lin Li, Yichen Pan, Ping Yang
Summary: The purpose of this article is to find a measure to improve the interfacial thermal transfer of graphene/silicon heterojunction. Through molecular dynamics simulation, it is found that surface modification can significantly reduce the thermal resistance, thereby improving the thermal conductivity of the graphene/silicon interface.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Qiong Wu, Yancheng Wang, Haonan Zhou, Xingye Qiu, Deqing Mei
Summary: This article introduces a visible methanol steam reforming microreactor, which uses an optical crystal as an observation window and measures the reaction temperature in real-time using infrared thermography. The results show that under lower oxygen to carbon ratio conditions, the microreactor has a higher heating rate and a stable gradient in temperature distribution.
APPLIED THERMAL ENGINEERING
(2024)
Review
Thermodynamics
Giulia Manco, Umberto Tesio, Elisa Guelpa, Vittorio Verda
Summary: In the past decade, there has been a growing interest in studying energy systems for the combined management of power vectors. Most of the published works focus on finding the optimal design and operations of Multi Energy Systems (MES). However, for newcomers to this field, understanding how to achieve the desired optimization details while controlling computational expenses can be challenging and time-consuming. This paper presents a novel approach to analyzing the existing literature on MES, with the aim of guiding practical development of MES optimization. Through the discussion of six case studies, the authors provide a mathematical formulation as a reference for building the model and emphasize the impact of different aspects on the problem nature and solver selection. In addition, the paper also discusses the different approaches used in the literature for incorporating thermal networks and storage in the optimization of multi-energy systems.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xuepeng Yuan, Caiman Yan, Yunxian Huang, Yong Tang, Shiwei Zhang, Gong Chen
Summary: In this study, a multi-scale microgroove wick (MSMGW) was developed by laser irradiation, which demonstrated superior capillary performance. The surface morphology and performance of the wick were affected by laser scan pitch, laser power, repetition frequency, and scanning speed. The MSMGW showed optimal capillary performance in alumina material and DI water as the working fluid.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Maofei Mei, Feng Hu, Chong Han
Summary: This paper proposes an effective local search method based on detection of droplet boundaries for understanding the dynamic process of droplet growth during dropwise condensation. The method is validated by comparing with experimental data. The present simulation provides an effective approach to more accurately predict the nucleation site density in future studies.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Rahul Kumar Sharma, Ashish Kumar, Dibakar Rakshit
Summary: The study explores the use of phase change materials (PCM) as a retrofit with Heating Ventilation and Air-conditioning systems (HVAC) to reduce energy consumption and improve air quality. By incorporating PCM with specific thickness and fin configurations, significant energy savings can be achieved in comparison to standard HVAC systems utilizing R134a. This research provides policymakers with energy-efficient and sustainable solutions for HVAC systems to combat climate change.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Zhenhua Ren, Xiangjin Meng, Xingang Qi, Hui Jin, Yunan Chen, Bin Chen, Liejin Guo
Summary: This paper investigates the heat transfer mechanism and factors influencing thermal radiation in the process of supercritical water gasification (SCWG) of coal, and proposes a comprehensive numerical model to simulate the process. Experimental validation results show that thermal radiation accounts for a significant proportion of the total heat exchange in the reactor and a large amount of radiant energy exists in the important spectral range of supercritical water. Enhancing radiative heat transfer can effectively increase the temperature of the reaction medium and the gasification rate.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Mauro Abela, Mauro Mameli, Sauro Filippeschi, Brent S. Taft
Summary: Pulsating Heat Pipes (PHP) are passive two-phase heat transfer devices with a simple structure and high heat transfer capabilities. The actual unpredictability of their dynamic behavior during startup and thermal crisis hinders their large-scale application. An experimental apparatus is designed to investigate these phenomena systematically. The results show that increasing the number of evaporator sections and condenser temperature improves the performance of PHP. The condenser temperature also affects the initial liquid phase distribution and startup time.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Ke Gan, Ruilian Li, Yi Zheng, Hui Xu, Ying Gao, Jiajie Qian, Ziming Wei, Bin Kong, Hong Zhang
Summary: A 3-dimensional enhanced heat pipe radiator has been developed to improve heat dissipation and temperature uniformity in cooling high-power electronic components. Experimental results show that the radiator has superior heat transfer performance compared to a conventional aluminum fin radiator under different heating powers and wind speed conditions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xinyi Zhang, Shuzhong Wang, Daihui Jiang, Zhiqiang Wu
Summary: This study focuses on recovering waste heat from blast furnace slag using dry centrifugal pelletizing technology. A comprehensive two-dimensional model was developed to analyze heat transfer dynamics and investigate factors influencing heat exchange efficiency. The findings have important implications for optimizing waste heat recovery and ensuring safe operations.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xincheng Wu, An Zou, Qiang Zhang, Zhaoguang Wang
Summary: The boosting heat generation rate of high-performance processors is challenging traditional cooling techniques. This study proposes a combined design of active jet intermittency and passive surface modification to enhance heat transfer.
APPLIED THERMAL ENGINEERING
(2024)
